Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.6.5.3 (complex I)
8,901 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two long and uninterrupted reading frames, specifying the ND1 and RTL genes, are embedded within fragmented rRNA genes in the 15.8-kb mitochondrial genome of Chlamydomonas reinhardtii, a unicellular green alga. The ND1 gene encodes a subunit of respiratory NADH dehydrogenase, a standard mitochondrial gene, while the RTL gene is related to the reverse transcriptase-like part of some optional introns and plasmids in fungal mitochondria. The universal genetic code is used in both the ND1 and RTL genes; however, the latter is distinguished from the other protein coding genes of C. reinhardtii mtDNA by several characteristics which suggest that RTL may be a more recently acquired gene. Flanking each of the protein coding genes, whose mRNAs are of similar abundance, are some of the 'scrambled' rRNA gene pieces that are a unique feature of C. reinhardtii mtDNA. These sub-genic modules give rise to high-abundance, small-sized pieces of rRNA, which are not spliced in this genetic system. Judging by the observed juxtaposition of transcripts as they hybridize to the genome, the mature rRNA and mRNA species from this region appear to be generated by precise endonucleolytic cleavages of a long RNA precursor. We suggest a model, involving reverse transcription of rRNAs and insertion of the resulting cDNAs into the mitochondrial genome, that might account for the pattern of dispersed rRNA gene pieces in C. reinhardtii mitochondrial DNA.
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PMID:Genes encoding a subunit of respiratory NADH dehydrogenase (ND1) and a reverse transcriptase-like protein (RTL) are linked to ribosomal RNA gene pieces in Chlamydomonas reinhardtii mitochondrial DNA. 246 63

The nucleotide sequence of a segment of the mitochondrial DNA (mtDNA) molecule of the liver fluke Fasciola hepatica (phylum Platyhelminthes, class Trematoda) has been determined, within which have been identified the genes for tRNA(ala), tRNA(asp), respiratory chain NADH dehydrogenase subunit I (ND1), tRNA(asn), tRNA(pro), tRNA(ile), tRNA(lys), ND3, tRNA(serAGN), tRNA(trp), and cytochrome c oxidase subunit I (COI). The 11 genes are arranged in the order given and are all transcribed from the same strand of the molecule. The overall order of the F. hepatica mitochondrial genes differs from what is found in other metazoan mtDNAs. All of the sequenced tRNA genes except the one for tRNA(serAGN) can be folded into a secondary structure with four arms resembling most other metazoan mitochondrial tRNAs, rather than the tRNAs that contain a T psi C arm replacement loop, found in nematode mtDNAs. The F. hepatica mitochondrial tRNA(serAGN) gene contains a dihydrouridine arm replacement loop, as is the case in all other metazoan mtDNAs examined to date. AGA and AGG are found in the F. hepatica mitochondrial protein genes and both codons appear to specify serine. These findings concerning F. hepatica mtDNA indicate that both a dihydrouridine arm replacement loop-containing tRNA(serAGN) gene and the use of AGA and AGG codons to specify serine must first have occurred very early in, or before, the evolution of metazoa.
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PMID:Platyhelminth mitochondrial DNA: evidence for early evolutionary origin of a tRNA(serAGN) that contains a dihydrouridine arm replacement loop, and of serine-specifying AGA and AGG codons. 254 89

Inheritance of the mitochondrial genome is known to be exclusively maternal. To determine whether the loss of paternal mitochondria could be due to a deficiency of RNA in the spermatozoal mitochondria, the expression of mitochondrial genes was studied in testicular cells at various stages of spermatogenesis and in epididymal spermatozoa. The presence of mitochondrial transcripts was examined by Northern blot analysis using probes for the following mitochondrially encoded genes: 12 S and 16 S ribosomal RNAs and a group of mRNAs including cytochrome oxidase subunits I and II (COI-COII), cytochrome b (cyt b), adenosine triphosphatase (ATPase) subunits 6 and 8, and subunit 1 of the respiratory chain NADH dehydrogenase (ND1). Comparison of total testicular RNA preparations from prepuberal (6, 8, 12, 16, 18, 20, 22, and 30 days old) and sexually mature (45 days old) mice revealed no major qualitative or quantitative differences in the levels of the mitochondrial transcripts described above. Similar results were observed from enriched preparations of type A and B spermatogonia and interstitial cells obtained from the testes of 8-day-old mice. Transcripts for COI-COII, ATPase 6, or ND1 were reduced in amount in the enriched preparations of pachytene spermatocytes, round spermatids, and residual bodies when compared to the amount in total testis or liver RNA. Transcripts of all the mitochondrial genes analyzed were present in RNA preparations isolated from sperm midpiece tails obtained after sonication of epididymal spermatozoa. These studies demonstrate that (a) during testicular development the levels of mitochondrial RNA in total testicular extracts show no major qualitative and quantitative differences; (b) the mitochondrial transcripts in enriched populations of type A and type B spermatogonia are not different from those obtained from total testes extracts; (c) mitochondrial transcript levels gradually decrease in enriched preparations of pachytene spermatocytes, round spermatids, and residual bodies; and (d) the mitochondrial rRNAs and mRNAs encoded by several mitochondrial genes can be isolated from sperm midpiece tails.
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PMID:Mitochondrial gene expression in male germ cells of the mouse. 277 68

We characterized the genes in the regions of large inverted repeats (IRA and IRB, 10,058 base-pairs each) and a small single copy (SSC 19,813 bp) of chloroplast DNA from Marchantia polymorpha. The inverted repeat (IR) regions contain genes for four ribosomal RNAs (16 S, 23 S, 4.5 S and 5 S rRNAs) and five transfer RNAs (valine tRNA(GAC), isoleucine tRNA(GAU), alanine tRNA(UGC), arginine tRNA(ACG) and asparagine tRNA(GUU)). The gene organization of the IR regions in the liverwort chloroplast genome is conserved, although the IR regions are smaller (10,058 base-pairs) than any reported in higher plant chloroplasts. The small single-copy region (19,813 base-pairs) encoded genes for 17 open reading frames, a leucine tRNA(UAG) and a proline tRNA(GGG)-like sequence. We identified 12 open reading frames by homology of their coding sequences to a 4Fe-4S-type ferredoxin protein, a bacterial nitrogenase reductase component (Fe-protein), five human mitochondrial components of NADH dehydrogenase (ND1, ND4, ND4L, ND5 and ND6), two Escherichia coli ribosomal proteins (S15 and L21), two putative proteins encoded in the kinetoplast maxicircle DNA of Leishmania tarentolae (LtORF 3 and LtORF 4), and a bacterial permease inner membrane component (encoded by malF in E. coli or hisQ in Salmonella typhimurium).
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PMID:Structure and organization of Marchantia polymorpha chloroplast genome. IV. Inverted repeat and small single copy regions. 319 37

The mitochondrial DNA (mtDNA) from Paracentrotus lividus (sea urchin) eggs, a circular molecule of about 15,500 bp, has been cloned in plasmid vectors after cleavage with various restriction enzymes. By a combination of Northern blot hybridization and nucleotide sequence analysis we have characterized most of the P. lividus mitochondrial transcripts and determined the basic gene organization of the mtDNA. The nucleotide sequence of a gene for one NADH dehydrogenase (ND) subunit, ND4L, has also been determined. Our results show the existence of a novel gene order. The 12S and 16S rRNA genes are not contiguous but are separated from each other by ND1 and ND2 genes. The ND4L gene is not adjacent to ND4 but is located between the tRNAArg gene and the gene for subunit II of cytochrome oxidase (CoII). The tRNA genes are reshuffled and contrary to all vertebrate mitochondrial genomes studied so far, there are no intergenic regions between the tRNAPhe and the cytochrome b genes. These characteristics suggest a peculiar mechanism for the regulation of gene expression in this organism and provide information on the evolution of the mitochondrial genetic system in animal cells.
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PMID:A novel gene order in the Paracentrotus lividus mitochondrial genome. 359 50

Treatment of rats with hydroxycobalamin[c-lactam] (HCCL), a cobalamin antagonist, results in both increased hepatic mitochondrial content and the development of defects in mitochondrial ubiquinol:cytochrome c oxidoreductase and cytochrome c oxidase. The present study was designed to evaluate changes in hepatic mitochondrial RNA contents in response to HCCL treatment in rats. After 2 weeks of HCCL treatment, hepatic contents of the mature mitochondrial mRNAs (expressed normalized to 28 S rRNA) encoding subunit II of cytochrome c oxidase (CO II), subunit 1 of NADH dehydrogenase (ND1), and cytochrome b were reduced to values 40-60% of those observed in RNA from control liver tissue. In addition, HCCL induced a pronounced accumulation of high molecular weight RNA species which hybridized to mitochondrial probes and represented polycistronic RNA sequences. The polycistronic RNAs were products of the heavy strand of the mitochondrial genome, and major species demonstrated hybridization patterns consistent with identifications corresponding to the 12-16 S rRNA, 12-16 S-ND1, 16 S-ND1, and CO II-ATP synthase subunit 6 regions of the mitochondrial genome. Maximal expression of the polycistronic mitochondrial RNA was observed after 2 weeks of HCCL treatment. Thus, HCCL treatment interferes with mitochondrial RNA processing and decreases the content of mature mitochondrial mRNAs. Altered expression of the mitochondrial genome may be responsible for the decreased electron transport chain activity known to result from HCCL administration.
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PMID:Hepatic cobalamin deficiency induced by hydroxycobalamin[c-lactam] treatment in rats is associated with decreased mitochondrial mRNA contents and accumulation of polycistronic mitochondrial RNAs. 750 36

The genes encoding the NADH dehydrogenase subunits of respiratory complex I have not been identified so far in the mitochondrial DNA (mtDNA) of yeasts. In the linear mtDNA of Candida parapsilosis, we found six new open reading frames whose sequences were unambiguously homologous to those of the genes known to code for NADH dehydrogenase subunit proteins of different organisms, i.e., ND1, ND2, ND3, ND4L, ND5, and ND6. The gene for ND4 also appears to be present, as judged from hybridization experiments with a Podospora gene probe. Specific transcripts from these open reading frames (ND genes) could be detected in the mitochondria. Hybridization experiments using C. parapsilosis genes as probes suggested that ND genes are present in the mtDNAs of a wide range of yeast species including Candida catenulata, Pichia guilliermondii, Clavispora lusitaniae, Debaryomyces hansenii, Hansenula polymorpha, and others.
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PMID:NADH dehydrogenase subunit genes in the mitochondrial DNA of yeasts. 752 69

We have identified a point mutation at nucleotide position 3460 in the ND1 gene of complex I in a Japanese pedigree with Leber's hereditary optic neuropathy by sequencing the ND genes in mitochondrial DNA. None of the 60 healthy Japanese had the 3460 mutation. The proband and his mother also had the 7444 mutation in the COI gene of complex IV and became nearly blind at age 19 with visual acuities of 0.02 OD and 0.04 OS We screened 30 patients with bilateral optic atrophy for the 3460 mutation, and identified one male patient who had the 3460 mutation in heteroplasmic fashion without carrying the 7444 mutation. He lost his sight at age 14 but it recovered to 1.2 OD and 0.7 OS about two years and half after the onset. The difference in final visual acuity between these two patients may reflect the degree of reduction in mitochondrial energy production.
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PMID:[Molecular genetic analysis of Leber's hereditary optic neuropathy with the 3460 mutation in Japanese pedigrees]. 761 Oct 10

We have sequenced a region (7,376-bp) of the mitochondrial (mt) DNA (54 kb) of the cellular slime mold, Dictyostelium discoideum. From the DNA and amino-acid sequence comparisons with known sequences, genes for ATPase subunit 9 (ATP9), cytochrome b (CYTB), NADH dehydrogenase subunits 1, 3 and 6 (ND1, ND3 and ND6), small subunit rRNA (SSU rRNA) and seven tRNAs (Arg, Asn, Cys, Lys, f-Met, Met and Pro) have been identified. The sequenced region of the mtDNA has a high average A + T-content (70.8%). The A + T-content of protein-genes (73.6%) is considerably higher than that of RNA genes (61.3%). Even with the strong AT-bias, the genetic code employed is most probably the universal one. All seven tRNAs are able to form typical clover leaf structures. The molecular phylogenetic trees of CYTB and SSU rRNA suggest that D. discoideum is closer to green plants than to animals and fungi.
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PMID:Codon usage, genetic code and phylogeny of Dictyostelium discoideum mitochondrial DNA as deduced from a 7.3-kb region. 773 10

The mitochondrial complex I genes were sequenced in seven Leber hereditary optic neuroretinopathy (LHON) families without the ND4/11,778 and ND1/3460 mutations. Four replacement mutations restricted only to LHON families were found, one in the ND1 gene at nt 4025, and three in the ND5 gene at nt 12,811, 13,637, and 13,967. The mutations did not change evolutionarily conserved amino acids suggesting that they are not primary LHON mutations in these families. They may be considered as secondary LHON mutations serving as exacerbating factors in an appropriate genetic background. A complex III mutation, cyt b/15,257, has been suggested to be one of the primary mutations causing LHON. Its presence was determined for 23 Finnish LHON families, and it was detected in two families harboring the ND4/11,778 mutation. Similarly, complex IV mutation COI/7444 was screened in Finnish LHON families, and it was found in one family carrying the ND1/3460 mutation.
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PMID:The spectrum of mitochondrial DNA mutations in families with Leber hereditary optic neuroretinopathy. 790 Nov 41


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